Cbaokinq ptteuace



Aug; 2s, 19.23.`

F. PFEIFER CRACKING FURNACE Filed May l, 1922 ///.s Hrm/Swix Patented Aug. 2S, 1923.

l .UNITED srarss A FRANK PFEIFER, OF MINNEAPOLIS, MINNESOTA.`

CRACKING- FURNACE.

Application filed May 1,

T 0 all zo/710m t ymay concer/nl:

Re it hereby known that l, FRANK Prnrrnn, a citizen of the United States7 and a resident ot Minneapolis, in the county ot Hennepin and State ot Minnesota, have invented a new and usetul Cracking Furnace, of which the followingis a specitication.

This invention relates more particularly to furnaces for cracking or breaking down vegetable matter and driving ott' by means of heat certain volatile compounds.

The object of my invention is to provide an exceedingly simple, cheap and etlicient furnace in which vegetable matter may be placed and subjected to heat until all desirable volatile mattei' has been driven oil.

A further object is to'so construct my furnace that the matter beingrtreated will itself act as a heat retainer.,` thereby eliminating the expensive insulation now required. y

Another object is to so construct the turnace tha-tf the tilling and cleansing of the retort and thestoking ot the furnace may be accomplished with a minimum expenditure of labor.

Still another object is to so construct the furnace that combustion ot the heating material will be complete within the furnace7 thereby avoiding undue loss ot heat by reducing the stack temperature.

l accomplish these results in the manner set torth in the 'following speciiication and illustrated in the accompanying drawing, in which:

Figure 1 is a vertical section through the machine with a portion of the trout not cut away to showy a tlap valve. lFigure 2 is a trent elevation with a portion cut away in section along the line 2-2 in Fig. 1.

Similar numbers ot reference refer to the saine or similar parts throughout the views.

Referring in detail to the drawing. l have constructed my furnace of a curved shell 10 having the straight sides 11 which extend to the floor line. A back 12 is welded along the flanged odge 1R to the shell 10. A, 'front 14 is also welded along the .flanged edge 15 to the shell 10. An angle iron arch 16 on the inside ol the shell 10 supports same inid wav between the ends 12 and 11i.

The tiring chamber is constructed ot a smaller shell 1.7 inside of the la rger shell 10. The straight sides 18 ot the shell 17 turn outwardly to formthe floors 19 and then downwardly walls 20 along the inside et 1922. Serial No. 557,536.

the side walls 1l to which they are secured. Angle irons 2l are lsecured to the lower and inner sides oi' the walls 20. A central di riding wall 22 extends Atrom `the floor lino to the under side ol the floors 19 and up between the walls 1S and forms a baille tor the tire box. Anglo irons 23 on the Yliront 11i and the wall 22 support the grate bars 2t which till the space between the walls 18 in :front o1 the wall 22. i

The furnace fire is ted through the squar chute 25 which projects l'rom the front- 14 and is"providedV with' a llarcd edge 26 and has a lire door 2T hinged at the top and opening inwardly when i straw is pushed agaii'ist same in stoliing. Retort doors 28 are provided near the middle of the side walls and are preferably placed so that the vegetable carbon residue remaining in the retort Aat'ter a charge has been treated can easily be removed through the doors 2S. It will be unlflcrstood that the retort includes the space between the shells 10 and 17 and above the floors 19.

A retort charging door 29 is provided on the trout lst. Rising from the rear of the shell 17 is a flue 30 which turns a. right angle bend into the horizontal flue l1 which also bends squarely and upwardly to 'form the liuc 32 which projects above the top ot. the shell 10. A stack 33 which is ot any suitable height depending upon local conditions is placed over the projecting top oit the flue 32. A. threaded Coup-lingI Sil is welded into the shell l0 above the tlue 30. A testing cock and a tlap check valve 36 are also provided on the Yliront 14; and open into the retort.

The space below the floors 19 and behind the walls 82 may be filled with earth if desired. An aslrpit door 37 is also provided.

The operation ot my device is as follows: The space between. the shells 10 and 17 and above the floors 19 is charged with straw, or vegetable mattei' ot any kind. and the doors 2S and 29 securely closed. A tire of straw or other material. or eren gas produced by the turnace itsel't. is made over the grates 24 and maintained until gas ceases to generate. This point can be ascertained by opening the test cock 35. the volatile matter being. ot course. passed out of the coupling 34 from which it is carried to suitable condensers and washers and into a gasometer from which it is drawn as required.

As the furnace cools the llap check Valve 36 admits air to the retort and prevents the gas from being drawn back through thel coupling` or the collapsing of the outer shell itself. f

plete combustion within the furnace and the-y resultingv low stark temperature was to use the square` turns in the smoke discharge dues 30, 3l and 32. Itis evident that instead -ofpassing directly out to the atmosphere the burning gases form into eddy eurrents at these points which delay their escape from the furnace, with very. desirable results.

It is evident that these furnaces can be employed in batteries and that the manufactured gas itself can be used as a heating nie-v dium, as above stated, without departing fromlthe 'spirit of my invention.

I am aware that manyvkinds of furnaces are used for breaking down Vegetable mat- Y ter, I'therefore do not claim same broadly but only intend that it shall cover those forms and modifications which fall fairly within the appended `claims.

'lVhat I claim as new is:

l, AIn' a cracking y furnace, the eombination of a wagon top outer shell havingran internal `combustion chamber extending; its lulllength with `a smolre flue leading from therear of said combustion `chamber out to the atmosphere through the forward end of said wage-n top shell, `a charging door .at the `forward 'end of said shellabove said mimbustion chamber, and elefanout doors in the' sides ofsaid wagon itop shell.

Ina Cracking. furnace, the combination of a wagon `top outer shell with. a similarly shaped combustion Y'box supported within said outer shell, said `eon'ibustiori chamber havinits smoke flue at itsrear top and leading forward and upward through the outer shell, the space between said shell and above the `bottom of the rCombustion chamber' forming a. retont, charging 1 and eleanout doors for said retort, a baliie near the middle 'of said Combustiony chamber,

` Qrates in front Aof said baille, a gas outlet side a self closing door adapted to be` opened by pressure from the outside.'

3. In a crashing furnace, the combination of a wagon -t-op outer shell having a raised floor, combustion chamber entend ing Ithe *full length of said outer shell, a transverse dividing wall under the middle of said raised floor extending upinte said combustion chamber in the form of. a baille, grates in said combustion Chamber in fro-nt of said baffle, a` stoling chute in the front of said oulter shell opening, into said eom bustion Chamber, aself-elosing door in said stoking chute, a smoke vflue having square bends adapted to carry smoke from the rear of said combustion Chamber to the front of saidouter shell, and a cheek Valve opening into the retort formed between the outer shell and the combustion chamber.

4; A Cracking furnace having a relatively loin firing Compartment- .aind having a bai'lle near its center and grates in front of said baille, and h ying a.v ret-ort formed overand along the sides of said ringl com-v partment, `and flue means for carrying; burned gases from said firing: Compartment through said 'retort and out to the` atmosphere.v

5. In a cracking furnace, the combination of a pair of side walls joined by a rounded top 'andfha'ving end walls at both ends of said" side walls, with an internaliring Compartment ,consisting of a pair of side walls united by a round top said side walls being; turned 01..'ituf'ardly at their feet and downwardly against the inside of said outer walls, said flirin.;T compartment mem bers Vbeing `joined at their ends to the fron? and rear end walls, a transverse halide wall near `the middle of said frame ventending; fronithe floor line` to wellup into the liring ("empartment grates in yfront of' said baille. a stoling;a eliutein the 'front wall over said gratos, a square angled return flue from'the rear top of said firing,r 'compartment to the front of said rounded top, a port for the escape of generated Agms, a Charging' door over the stolrinp; chute, and a pair'of clean- Oui/ doors iin the voutside walls near` their middles.

FRANK PFETFER. 

